From c3d4fdb4c1d1d31c45f68d229ec2686fb0498a43 Mon Sep 17 00:00:00 2001
From: "Paul Gauthier (aider)" <paul@aider.chat>
Date: Thu, 8 May 2025 14:25:14 -0700
Subject: [PATCH] fix: Preserve original read-only files across symlinks

---
 aider/commands.py | 33 ++++++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/aider/commands.py b/aider/commands.py
index 7a7a738c3..3dd370e51 100644
--- a/aider/commands.py
+++ b/aider/commands.py
@@ -81,8 +81,20 @@ class Commands:
         self.help = None
         self.editor = editor
 
-        # Store the original read-only filenames provided via args.read
-        self.original_read_only_fnames = set(original_read_only_fnames or [])
+        # Store the original read-only filenames provided via args.read.
+        # Keep both the raw path as given and the canonical realpath so we
+        # can match them later even when symlinks (eg /var ↔ /private/var)
+        # are involved.
+        self.original_read_only_fnames = set()
+        for fname in original_read_only_fnames or []:
+            # As provided
+            self.original_read_only_fnames.add(str(fname))
+            # Canonical path (best-effort)
+            try:
+                self.original_read_only_fnames.add(os.path.realpath(fname))
+            except Exception:
+                # Ignore paths that cannot be resolved
+                pass
 
     def cmd_model(self, args):
         "Switch the Main Model to a new LLM"
@@ -411,16 +423,23 @@ class Commands:
     def _drop_all_files(self):
         self.coder.abs_fnames = set()
 
+        # Helper to compare two paths while ignoring symlinks/resolution.
+        def _paths_match(p1, p2):
+            try:
+                return os.path.samefile(p1, p2)
+            except (FileNotFoundError, OSError):
+                return os.path.normpath(p1) == os.path.normpath(p2)
+
         # When dropping all files, keep those that were originally provided via args.read
         if self.original_read_only_fnames:
-            # Keep only the original read-only files
             to_keep = set()
             for abs_fname in self.coder.abs_read_only_fnames:
                 rel_fname = self.coder.get_rel_fname(abs_fname)
-                if (
-                    abs_fname in self.original_read_only_fnames
-                    or rel_fname in self.original_read_only_fnames
-                ):
+                keep = any(
+                    _paths_match(abs_fname, orig) or rel_fname == orig
+                    for orig in self.original_read_only_fnames
+                )
+                if keep:
                     to_keep.add(abs_fname)
             self.coder.abs_read_only_fnames = to_keep
         else: